Card edge connectors typically contain contact elements having a first contact portion that either extends through the connector for insertion into another printed circuit board or is configured to mate with a terminal member in a complimentary connector and a second contact portion comprising a cantilever beam extending outwardly along a card receiving slot. The contact surface is located on the beam inwardly from the free end thereof and engages conductive traces on the printed circuit card. The convex surface on the beam provides a metal to metal mating area for good wiping action as the beam engages the card and for good electrical contact therewith. To enable high density interconnections, card edge connectors may also be provided with a plurality of rows of such cantilevered beams wherein an inner or first set of cantilevered beams extend outwardly a first distance along the card receiving slot and an outer or second set of cantilevered beams extend outwardly a second distance along the card receiving slot. Each set of cantilevered beams, therefore, can engage different contact pads on the surface of a circuit card inserted into the card receiving slot.
Typically this type of connector is made by first inserting the rows of contact elements that include the inner set of cantilevered beams into inner rows of terminal receiving passageways of a housing and then inserting the contact elements having the outer set of cantilevered beams into corresponding outer rows of terminal receiving passageways of the housing. Contact elements having essentially straight leads or pins for the first contact portion may be loaded into the housing from the card receiving edge, thus enabling the cantilevered beam to be formed prior to loading the contact element into the housing. Contact elements having a socket or a shape other than an essentially straight member for the first portion, however, are typically loaded from the opposite side or mating face of the housing. The latter approach requires that the cantilevered beam portions be formed after the contact elements have been loaded into the housing. To facilitate the forming process, the inner rows of contacts with their respective cantilevered beam portions are formed prior to loading of the outer rows of contact elements or terminal members into the housing. It is therefore necessary to provide means for preventing damage to the inner rows of terminals during the loading and forming of the outer rows of contact elements.
In addition to problems with loading the contact elements into the terminal housing, problems are also occur in trying to solder each one of the cantilevered beams to the appropriate locations on the inserted circuit board. The bulk of the cantilevered beams on the outside rows hinder the accessibility of the inner rows of beams during the soldering process, particularly if the contact elements are spaced closely together such as for example in what is termed in the art as high density connectors.
It is desirable therefore to have a means for making high density connectors that minimizes damage to other contact elements during the manufacturing process.
It is also desirable to have a cost effective means for making an electrical connector that requires a minimum of processing steps.
It is desirable therefore to have a means whereby double sets of cantilevered beams may be provided in a connector which may be soldered without interference from adjacent rows of cantilevered beams.
It is also desirable to have a method of assembling and forming the cantilevered beams wherein the previously formed beams are not subjected to damage during the forming of the subsequent pairs of cantilevered beams.